Semiconductor and other types of electronic devices are commonly encapsulated wholly or partly in plastic resin (i.e., mold compound) to form an integrated electronic package (also referred to as an integrated circuit, IC, chip, or microchip). The plastic resin encapsulation material provides environmental protection and facilitates connection between such integrated electronic packages and external circuits. Electrical contacts for connection with external circuits are exposed at an exterior surface of an integrated electronic package and are connected internally with electrical contact pads on a semiconductor chip or die within the package. Various techniques are available for internally connecting the embedded electronic devices with the exposed electrical contacts of the integrated electronic package.
One technique for connecting the exposed electrical contacts with electrical contact pads on, for example, a semiconductor die entails temporarily placing singulated semiconductor dies with their active side on a support. The dies are embedded with a molding compound to form a comparatively flat or planar panel assembly, which is subsequently released from the temporary support. The contact pads on the semiconductor die surfaces are then connected to exposed pads on the exterior surface of the panel assembly by a redistribution process to appropriately route the signal connections, and the power and ground connections. The redistribution process (also referred to as a buildup process) includes deposition of a plurality of electrically conductive layers by electroplating techniques and patterning using batch process lithography. The electrically conductive layers are separated by insulating layers.
In certain types of electronic device packaging, a problem, referred to as “warping,” can occur during the encapsulation and formation of the panel assembly. If the panel assembly has warped during encapsulation, the process of adding the electrically conductive layers using the redistribution process can be adversely affected, thereby reducing overall yield and increasing manufacturing costs. As such, control or elimination of warping is important to achieving high manufacturing yields and low manufacturing costs in such encapsulated planar assemblies.
An embedded ground plane (EGP) is sometimes built into a panel assembly. The EGP is used to limit warpage of the panel assembly, control die drift, and can also be used to provide a single routing option for ground in a finished semiconductor package. Typically, such EGP's are fabricated from copper. Unfortunately, the use of a copper EGP can lead to relatively high manufacturing and tooling costs, undesirably high rate of saw blade wear during package singulation due to material hardness, and high thermal expansion.